The overall objective of the research proposal is the isolation and identification of fungi, especially members of the penicillia which produce toxic and/or carcinogenic metabolites. The preparation of actively toxic materials and the chemical identification of the toxins and carcinogens. Specific aims include the determination of the toxin produced by toxigenic isolates of Penicillium viridicatum; to determine if cultures of P. viridicatum will produce an increase in neoplasms in species other than the mouse; to determine the period of feeding required to increase the incidence of pulmonary tumors in mice fed culture of P. viridicatum; to determine the carcinogenic activity of fungal products of P. viridicatum where fed in combination with the mycotoxins sterigmatocystin and ochratoxin A; to determine the carcinogenic activity of extracts of penicillia infected subcutaneously.